Electronic sheet material dispensers are well know in the art, including dispensers that automatically dispense a metered length of towel or tissue material upon sensing the presence of a user. This type of dispenser has become known in the art as a “hands-free” dispenser in that it is not necessary for the user to manually actuate or otherwise handle the dispenser to initiate a dispense cycle. The control systems and mechanical aspects of conventional hands-free dispensers are wide and varied.
A common problem associated with conventional electronic dispensers is the buildup and discharge of static electricity generated during the dispense cycle. A static charge may be generated in the dispenser from any number of components or operations, such as the movement of the paper web over various rollers or other guide structure, interaction between guide rollers, and so forth. The static charge can be relatively small, or may be up to about thirty or more kilovolts. If not grounded or dissipated, this charge may result in the user receiving an unpleasant “static shock” when using the dispenser. The charge may also be detrimental to the dispenser's electronic control circuitry, particularly the relatively sensitive sensor circuitry.
Efforts have been made in the past to ground the charge-generating components of the dispenser, such as the drive roller, to a ground surface within or external to the dispenser. Other methods include grounding components through a ground connection of the electronic circuitry. These methods, however, require a readily accessible ground, such as an existing ground connection of a conventional AC power supply system, a grounded plumbing component, a dedicated grounding rod, or the like. Unfortunately, it is often the case that battery-powered electronic sheet material dispensers are not located in close proximity to a readily accessible ground connection. For example, the wall of a public restroom, or the walls of a toilet enclosure in the case of a toilet tissue dispenser, may not provide an accessible ground connection. In this situation other measures are necessary.
U.S. Pat. Nos. 6,871,815 and 7,017,856 propose a system wherein a low impedance, high-conductivity pathway (i.e., a wire) is used to connect internal components of the dispenser that are subject to static charge buildup to a mechanical contact on the back of the dispenser housing. This contact, in turn, makes contact with the supporting wall upon which the dispenser is mounted, with the premise being that any static charge will be dissipated by the wall.
The art is thus constantly seeking ways to improve upon conventional electronic sheet material dispensers, and the present disclosure relates to an alternative unique system and method for dissipating static charge buildup in such dispensers.